Preheat oven to 425°
Add the salt, baking soda and baking powder to about 1½ cups of sifted flour.
With a fork or pastry blender, cut shortening into the dry mix, not so much as to blend it, but to get the shortening broken down into smaller pieces, covered in the flour.
When it's a crumb texture with no lumps larger than a pea, add the Sprite, lightly folding the mix to wet the crumbs.
Then add the buttermilk, slowly folding it in, not really stirring, to just wet the dough into a sticky single mass.
It may need a little more flour if it’s too sticky, but we can adjust now as we dump the dough out onto a floured countertop.
Slowly fold the mass onto itself, at least three times, to make the layers in your biscuits.
Add even more flour – only as needed – to keep the dough from sticking to your work surface, hands, and the biscuit cutter.
Pat out your dough to about ½ inch thick, or your desired thickness. With your biscuit cutter of choice, press quickly straight down, no twisting, and place all the raw biscuits, touching each other, on the preferred baking vessel. (Higher sides, like cast iron, will result in taller biscuits. Just like they climb up each other, they'll rise on the walls of the pan they're baked in as well.)
Take remaining dough, fold it back into a mass, flatten, and cut again, until there's none remaining.
Bake at 425° for about 12-15 minutes, until lightly golden brown, or modify time depending on your preference of color and doneness.
Top with plenty of strawberry jam and softened butter, and enjoy.